Macroeconomics Quiz: Market Equilibrium And Disequilibrium
20 questions · exam conditions
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Market Equilibrium And DisequilibriumQuestion 1 of 20

In a market where demand is perfectly inelastic and supply has normal positive slope, the government imposes a per-unit tax on sellers. Compared to a market with normal downward-sloping demand and identical supply, this tax will result in:

Higher tax revenue for the government because consumers cannot reduce their quantity demanded in response to price increases
Lower deadweight loss because the tax creates no inefficient reduction in trades between willing buyers and sellers
Identical consumer burden but lower producer burden because demand inelasticity prevents quantity adjustment
Higher total tax burden shared equally between consumers and producers regardless of the supply curve slope
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Macroeconomics Quiz

Macroeconomics Quiz: Market Equilibrium And Disequilibrium

Practice Market Equilibrium And Disequilibrium in Macroeconomics with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Market Equilibrium And Disequilibrium, giving you a quick way to practice the rules, question types, and explanations that matter most for Macroeconomics.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

In a market where demand is perfectly inelastic and supply has normal positive slope, the government imposes a per-unit tax on sellers. Compared to a market with normal downward-sloping demand and identical supply, this tax will result in:

  1. Higher tax revenue for the government because consumers cannot reduce their quantity demanded in response to price increases
  2. Lower deadweight loss because the tax creates no inefficient reduction in trades between willing buyers and sellers (correct answer)
  3. Identical consumer burden but lower producer burden because demand inelasticity prevents quantity adjustment
  4. Higher total tax burden shared equally between consumers and producers regardless of the supply curve slope
Explanation: With perfectly inelastic demand, quantity demanded doesn't change when price rises due to the tax. Since the same quantity is traded before and after the tax, no trades are eliminated, so there's no deadweight loss. Deadweight loss occurs when mutually beneficial trades are prevented by the tax, but with perfectly inelastic demand, all original trades still occur. Choice A is wrong because while tax revenue per unit may be the same, we can't assume higher total revenue without knowing quantities. Choice C is incorrect about burden distribution. Choice D wrongly claims equal burden sharing.

Question 2

A competitive market experiences a simultaneous increase in both demand and supply, with the new equilibrium showing higher quantity but unchanged price. Six months later, the government imposes a binding price ceiling at 90% of this equilibrium price. Compared to the situation immediately before the ceiling was imposed, the shortage created will be:

  1. Larger than it would have been at the original equilibrium because the demand and supply shifts increased the market's responsiveness to price changes
  2. Impossible to compare without knowing whether the demand shift was larger than the supply shift in absolute magnitude
  3. Identical to what it would have been at the original equilibrium because the price level determines shortage magnitude regardless of curve positions
  4. Smaller than it would have been at the original equilibrium because the rightward shift in supply increases quantity available at any given price (correct answer)
Explanation: When analyzing price ceilings and shortages, you need to understand how shifts in supply and demand curves affect the magnitude of shortages at any given price level. The key insight is that curve positions matter just as much as price levels. Let's trace through this scenario: Initially, both demand and supply increase equally (since quantity rises but price stays the same). This means both curves shift rightward. Now when the government sets a price ceiling at 90% of equilibrium price, you're looking at the same price level as before, but with different curve positions. The shortage equals the horizontal distance between the demand and supply curves at the ceiling price. Since supply shifted rightward, suppliers are now willing to provide more quantity at that 90% price level than they would have originally. Meanwhile, the demand curve also shifted right, but the net effect is that more goods are available at the ceiling price, creating a smaller shortage than would have occurred with the original curves. Answer D correctly identifies that the rightward supply shift increases quantity available at any given price, reducing the shortage magnitude. Answer A incorrectly focuses on "responsiveness to price changes" (elasticity), which isn't what determines shortage size. Answer B wrongly suggests we need to know the relative magnitude of shifts - we already know they were equal since price didn't change. Answer C makes the fundamental error of assuming curve positions don't matter for shortage calculations. Remember: shortages depend on both the price level AND the positions of the curves. Rightward supply shifts always reduce shortages at any given price.

Question 3

Two identical markets for widgets initially have the same supply and demand curves and equilibrium at price P0P_0 and quantity Q0Q_0. In Market 1, demand increases by 20%. In Market 2, demand increases by 20% and supply simultaneously increases by 10%. If supply elasticity is 0.5 and demand elasticity is -1.0 in both markets, which statement correctly compares the new equilibrium prices?

  1. Market 1 will have a higher price than Market 2 because it experiences only demand increases without supply offset effects (correct answer)
  2. Market 2 will have a higher price than Market 1 because the combined shifts create greater upward pressure on price
  3. Both markets will have identical prices because the elasticities are the same and determine price regardless of shift combinations
  4. The price relationship depends on the initial equilibrium price P0P_0, which determines how percentage changes translate to absolute changes
Explanation: In Market 1, only demand increases, creating upward pressure on price. In Market 2, demand increases (upward pressure) but supply also increases (downward pressure on price). Since both markets start identically, Market 2's supply increase partially offsets the price rise from demand increase, resulting in a lower final price than Market 1. The elasticities determine how much prices change, but don't eliminate the directional effects of the shifts. Choice B reverses the logic. Choice C wrongly suggests elasticities alone determine outcomes. Choice D incorrectly brings in initial price levels when we're dealing with percentage shifts.

Question 4

In a competitive market, the demand curve shifts rightward while supply simultaneously shifts leftward. The new equilibrium has a higher price but the same quantity as before. Three months later, with demand and supply curves unchanged from their new positions, the government implements a price floor exactly at the current equilibrium price. What is the immediate effect of this price floor?

  1. A surplus emerges because the price floor prevents the market from reaching its natural equilibrium at a lower price level
  2. A shortage develops because the price floor restricts quantity supplied while maintaining quantity demanded at previous levels
  3. No immediate disequilibrium occurs because the price floor coincides with the current market-clearing price (correct answer)
  4. Market efficiency decreases even without quantity changes because the price floor creates deadweight loss through altered consumer behavior
Explanation: When a price floor is set exactly at the current equilibrium price, it has no immediate effect because the market was already clearing at that price. The price floor only becomes binding (creates effects) if it's set above the equilibrium price. Since the floor equals the equilibrium, quantity demanded still equals quantity supplied, and no surplus or shortage emerges. Choice A incorrectly assumes the floor is above equilibrium. Choice B incorrectly predicts a shortage and misunderstands how price floors work. Choice D is wrong because a non-binding price floor creates no deadweight loss.

Question 5

Consider two markets: Market X has demand elasticity of -0.5 and supply elasticity of 1.5; Market Y has demand elasticity of -2.0 and supply elasticity of 0.5. If identical per-unit taxes are imposed in both markets and both markets have the same pre-tax equilibrium price and quantity, which statement correctly compares the post-tax outcomes?

  1. Market X will have greater deadweight loss because its combined elasticity is higher, leading to larger quantity distortions
  2. Market Y will have greater deadweight loss because demand is more elastic, causing consumers to reduce quantity more dramatically
  3. The markets will have identical deadweight loss because the sum of absolute elasticities is equal in both markets
  4. Market Y will have greater deadweight loss because the total elasticity of response to price changes is greater (correct answer)
Explanation: Deadweight loss from taxation depends on the total elasticity of response, measured as the sum of absolute values of demand and supply elasticities. Market X: |-0.5| + |1.5| = 2.0. Market Y: |-2.0| + |0.5| = 2.5. Since Market Y has greater total elasticity, the same tax will cause a larger quantity reduction and greater deadweight loss. Choice A incorrectly states Market X has higher combined elasticity. Choice B focuses only on demand elasticity, ignoring supply elasticity. Choice C incorrectly claims equal elasticity sums (2.0 ≠ 2.5).

Question 6

In a market for organic coffee, an initial equilibrium exists at price P0P_0 and quantity Q0Q_0. Simultaneously, consumer income increases (organic coffee is a normal good) and new technology reduces production costs. If the new equilibrium quantity is Q1>Q0Q_1 > Q_0 but the price remains unchanged at P0P_0, which of the following best describes the relative magnitudes of the demand and supply shifts?

  1. The demand shift was larger in magnitude than the supply shift, but both shifts were proportional to the price elasticity of demand
  2. The demand shift was exactly equal in magnitude to the supply shift, causing the price effects to cancel out completely (correct answer)
  3. The supply shift was larger than the demand shift, but the difference was offset by the income elasticity of demand
  4. The shifts were unequal, but their combined effect on price was neutralized by the cross-price elasticity with regular coffee
Explanation: When both demand increases (rightward shift) and supply increases (rightward shift) by exactly equal magnitudes, the upward pressure on price from increased demand is perfectly offset by the downward pressure from increased supply, leaving price unchanged. The quantity increases because both shifts contribute to higher equilibrium quantity. Choice A incorrectly relates shift magnitude to price elasticity. Choice C incorrectly involves income elasticity as an offsetting factor rather than recognizing equal shifts. Choice D incorrectly introduces cross-price elasticity, which is not relevant to this scenario.

Question 7

A market has linear demand and supply curves that intersect at price $40 and quantity 200 units. A price support program guarantees producers a minimum price of $50, with the government purchasing any excess supply at that price. If the price support reduces consumer purchases to 150 units while producers supply 250 units, what is the total cost to taxpayers of this program?

  1. The government purchases 100 units at $50 each, costing taxpayers exactly $5,000 (correct answer)
  2. The government purchases 100 units at $50 each, but taxpayers bear additional deadweight loss costs of $500
  3. The government cost is $5,000, but the total economic cost including deadweight loss is $5,500
  4. The direct cost is $5,000, but accounting for lost consumer surplus, the total burden exceeds $6,000
Explanation: The question asks specifically for the cost to taxpayers, which is the direct government expenditure. The government buys the excess supply: 250 (quantity supplied) - 150 (quantity demanded by consumers) = 100 units at $50 each = $5,000. While the program creates deadweight loss and affects consumer surplus, these are not direct costs to taxpayers but rather economic efficiency losses borne by society. Choices B, C, and D incorrectly include deadweight loss or consumer surplus changes as taxpayer costs rather than recognizing these as separate economic effects.

Question 8

A city imposes a price ceiling on apartment rents that is 15% below the current market equilibrium price. Six months later, the city council observes that the actual shortage is smaller than initially predicted by economists. Assuming the demand and supply curves have not shifted, which of the following best explains this observation?

  1. The price ceiling created a deadweight loss that reduced both consumer and producer surplus equally over time
  2. Market participants gradually adjusted to the disequilibrium through non-price mechanisms like rationing and search costs
  3. The initial economic analysis overestimated the price elasticities of both demand and supply in this market (correct answer)
  4. The price ceiling generated positive externalities that partially offset the allocative inefficiency of the policy
Explanation: The size of a shortage from a price ceiling depends directly on the price elasticities of demand and supply. If the shortage is smaller than predicted, the curves must be less elastic (more inelastic) than economists initially estimated. With more inelastic curves, the same price reduction creates a smaller gap between quantity demanded and quantity supplied. Choice A describes deadweight loss but doesn't explain why the shortage would be smaller. Choice B describes adjustment mechanisms but doesn't explain why the fundamental shortage would be reduced. Choice D incorrectly introduces externalities, which don't affect the basic supply-demand relationship.

Question 9

Market analysts observe that in the global market for coffee beans over the past year, the equilibrium price has decreased while the equilibrium quantity traded has increased. Which of the following events, ceteris paribus, could explain this outcome?

  1. A successful global advertising campaign highlighting the health benefits of coffee.
  2. A widespread adoption of a new, more productive coffee harvesting machine. (correct answer)
  3. A severe drought affecting major coffee-producing regions in Brazil and Vietnam.
  4. A significant decrease in the price of tea, a popular substitute for coffee.
Explanation: The observation is that equilibrium price (P) decreased and equilibrium quantity (Q) increased. We need to identify the cause that produces this specific outcome. (A) An increase in demand shifts D right, causing P to rise and Q to rise. (B) An increase in supply (e.g., from better technology) shifts S right, causing P to fall and Q to rise. This matches the observation. (C) A decrease in supply shifts S left, causing P to rise and Q to fall. (D) A decrease in demand shifts D left, causing P to fall and Q to fall.

Question 10

The market for a specific type of microchip is described by the following equations: Demand: Qd=100−2PQ_d = 100 - 2P and Supply: Qs=10+PQ_s = 10 + P. If the government imposes a $3 per-unit tax on the suppliers of these microchips, what will be the new equilibrium price paid by consumers?

  1. $33.00
  2. $31.00 (correct answer)
  3. $30.00
  4. $28.00
Explanation: First, find the initial equilibrium: 100 - 2P = 10 + P \Rightarrow 90 = 3P \Rightarrow P = \30.Thetaxonsupplierschangesthesupplyequation.Suppliersnowreceive. The tax on suppliers changes the supply equation. Suppliers now receive P_c - 3foreachunitsold,wherefor each unit sold, whereP_cisthepriceconsumerspay.Thenewsupplyequationisis the price consumers pay. The new supply equation isQ_s = 10 + (P_c - 3) = 7 + P_c.Setthisnewsupplyequaltotheoriginaldemand:. Set this new supply equal to the original demand: 100 - 2P_c = 7 + P_c \Rightarrow 93 = 3P_c \Rightarrow P_c = $31. The price paid by consumers is \31. Distractor A adds the full tax to the old price. Distractor C is the old equilibrium price. Distractor D is the price suppliers receive after the tax ($31 - $3 = $28).

Question 11

The government imposes a binding price ceiling on rental apartments in a city. Subsequently, a major technology firm opens a new headquarters in the city, leading to a large influx of new residents. What is the effect of the firm's arrival on the rental market, given the price ceiling?

  1. The price of rental apartments will increase toward the new, higher equilibrium level.
  2. The shortage of rental apartments will increase. (correct answer)
  3. The quantity of apartments rented will increase to meet the new demand.
  4. The price ceiling, which was previously binding, will become non-binding.
Explanation: A binding price ceiling is set below the equilibrium price, causing an initial shortage (quantity demanded > quantity supplied). The influx of new residents increases the demand for apartments, shifting the demand curve to the right. At the fixed ceiling price, the quantity demanded increases further, while the quantity supplied remains unchanged (as it's determined by the ceiling price). Therefore, the existing shortage becomes more severe.

Question 12

Assume automobiles are a normal good. The price of steel, a key input in automobile manufacturing, increases significantly. Simultaneously, a robust economic expansion leads to a widespread increase in consumer incomes. What is the combined effect on the market for new automobiles?

  1. The equilibrium price will increase, but the effect on equilibrium quantity is indeterminate. (correct answer)
  2. The equilibrium quantity will decrease, but the effect on equilibrium price is indeterminate.
  3. Both the equilibrium price and quantity will decrease.
  4. The equilibrium price will increase, and the equilibrium quantity will increase.
Explanation: The increase in the price of steel, an input, decreases the supply of automobiles, shifting the supply curve left. This puts upward pressure on price and downward pressure on quantity. The increase in consumer incomes increases the demand for automobiles (a normal good), shifting the demand curve right. This puts upward pressure on both price and quantity. Since both shifts cause the price to rise, the equilibrium price will definitely increase. The effect on quantity is indeterminate, as the supply shift decreases quantity while the demand shift increases it.

Question 13

A new government report highlights previously unknown health benefits of eating avocados, leading to a higher market price for them. How would this event be correctly represented on a supply and demand diagram for avocados?

  1. A rightward shift of the demand curve, resulting in an increase in the quantity supplied. (correct answer)
  2. A rightward shift of the supply curve, resulting in an increase in the quantity demanded.
  3. A rightward shift of the demand curve and a rightward shift of the supply curve.
  4. An upward movement along the demand curve, causing the supply curve to shift right.
Explanation: The report changes consumer tastes and preferences, which is a determinant of demand. This causes the demand curve to shift to the right (an 'increase in demand'). As the demand curve shifts along the fixed supply curve, the equilibrium point moves up and to the right. This movement along the supply curve is described as an 'increase in the quantity supplied', not an 'increase in supply'. This question tests the crucial distinction between a shift of a curve and a movement along a curve.

Question 14

In the market for corn, the demand is given by Qd=200−10PQ_d = 200 - 10P and the supply is given by Qs=50+5PQ_s = 50 + 5P, where P is the price per bushel. If the government establishes a price floor of $12 per bushel, what will be the result?

  1. A surplus of 30 bushels. (correct answer)
  2. A shortage of 30 bushels.
  3. A surplus of 60 bushels.
  4. The policy will have no effect on the market.
Explanation: First, find the equilibrium price by setting Qd=QsQ_d = Q_s: 200 - 10P = 50 + 5P \Rightarrow 150 = 15P \Rightarrow P = \10. Since the price floor of \12 is above the equilibrium price of $10, it is binding. At P = \12,thequantitydemandedis, the quantity demanded is Q_d = 200 - 10(12) = 80.Thequantitysuppliedis. The quantity supplied is Q_s = 50 + 5(12) = 110.Sincequantitysuppliedexceedsquantitydemanded,thereisasurplus.Thesizeofthesurplusis. Since quantity supplied exceeds quantity demanded, there is a surplus. The size of the surplus is Q_s - Q_d = 110 - 80 = 30$ bushels.

Question 15

The development of new drilling technology significantly reduces the cost of extracting natural gas. Natural gas is a key input for producing agricultural fertilizer and is also a primary substitute for coal in generating electricity. What are the most likely effects on the equilibrium prices in the markets for fertilizer and coal?

  1. The price of fertilizer will decrease, and the price of coal will decrease. (correct answer)
  2. The price of fertilizer will increase, and the price of coal will decrease.
  3. The price of fertilizer will decrease, and the price of coal will increase.
  4. The price of fertilizer will increase, and the price of coal will increase.
Explanation: The new technology increases the supply of natural gas, causing its price to fall. In the fertilizer market, natural gas is an input. A lower input price increases the supply of fertilizer, shifting its supply curve right and causing the equilibrium price of fertilizer to decrease. In the electricity market, natural gas is a substitute for coal. A lower price for natural gas will cause power plants to switch from coal to gas, decreasing the demand for coal. This shifts the demand curve for coal to the left, causing the equilibrium price of coal to decrease.

Question 16

The market for solar panels has demand Qd=500−5PQ_d = 500 - 5P and supply Qs=10P−100Q_s = 10P - 100, where P is the price in hundreds of dollars. The government provides a $300 per-unit subsidy (i.e., $3 hundred) to producers. What is the new equilibrium quantity of solar panels sold?

  1. 300
  2. 290
  3. 320
  4. 310 (correct answer)
Explanation: When you encounter subsidy problems, remember that subsidies to producers effectively shift the supply curve downward by the subsidy amount, making production cheaper at every quantity level. Start with the original market equilibrium. Setting Qd=QsQ_d = Q_s: 500−5P=10P−100500 - 5P = 10P - 100, which gives P=40P = 40 and Q=300Q = 300. With a 300subsidy(300 subsidy (3 hundred), producers receive $3 more per unit than the market price. If the market price is $PP ,producerseffectivelyreceive, producers effectively receive P+3P + 3 .Thesupplycurvebecomes:. The supply curve becomes: Qs=10(P+3)−100=10P+30−100=10P−70Q_s = 10(P + 3) - 100 = 10P + 30 - 100 = 10P - 70 $. Setting the new supply equal to unchanged demand: 500 - 5P = 10P - 70 . Solving: 570 = 15P , so P = 38 . The equilibrium quantity is Q = 500 - 5(38) = 310 . Looking at the wrong answers: Choice A (300) represents the original equilibrium quantity before the subsidy - a common trap for students who forget to account for the policy change. Choice B (290) might result from incorrectly subtracting the subsidy from supply instead of adding it, or from calculation errors. Choice C (320) could come from misapplying the subsidy amount or making arithmetic mistakes in the algebra. Study tip: Always remember that producer subsidies shift supply curves down (or right) by the subsidy amount, increasing equilibrium quantity and decreasing consumer price. Set up the new supply equation carefully by adding the subsidy to the price producers receive.

Question 17

In the market for laptop computers, a new, more efficient manufacturing process is invented. Concurrently, a new line of powerful tablet computers, which are a close substitute for laptops, is released and becomes very popular. What is the combined effect on the equilibrium price and quantity of laptop computers?

  1. Both the equilibrium price and quantity will decrease.
  2. The equilibrium quantity will increase, while the effect on equilibrium price is indeterminate.
  3. The equilibrium price will decrease, while the effect on equilibrium quantity is indeterminate. (correct answer)
  4. The equilibrium price will decrease, and the equilibrium quantity will increase.
Explanation: When you encounter supply and demand questions with simultaneous shifts, you need to analyze each change separately, then combine the effects. Here, you're dealing with both a supply shift (new manufacturing process) and a demand shift (substitute products becoming popular). The more efficient manufacturing process increases the supply of laptops, shifting the supply curve rightward. This alone would decrease price and increase quantity. Meanwhile, the popular new tablets serve as substitutes for laptops, decreasing demand for laptops and shifting the demand curve leftward. This alone would decrease both price and quantity. When you combine these effects, both shifts push price in the same direction (downward), making the price effect determinate—it will definitely decrease. However, the quantity effects work in opposite directions: increased supply pushes quantity up while decreased demand pushes quantity down. Without knowing the relative magnitude of these shifts, the net effect on quantity is indeterminate—it could increase, decrease, or stay the same depending on which shift is stronger. Answer C correctly identifies that price will decrease while quantity's direction is uncertain. Answer A incorrectly assumes quantity must decrease, ignoring the supply increase. Answer B mistakenly claims quantity will increase and gets the price effect wrong. Answer D incorrectly assumes quantity must increase, overlooking that decreased demand could outweigh the supply increase. Remember: when both curves shift, if they push the same variable in opposite directions, that variable's change is indeterminate. Always check each effect separately before combining them.

Question 18

In the market for cotton, a severe drought reduces the crop yield while a new international fashion trend significantly increases the demand for cotton clothing. After these events, market data shows that the total equilibrium quantity of cotton traded has decreased. What can be definitively concluded?

  1. The increase in demand was greater in magnitude than the decrease in supply.
  2. The decrease in supply was exactly equal in magnitude to the increase in demand.
  3. The equilibrium price of cotton must have decreased.
  4. The decrease in supply was greater in magnitude than the increase in demand. (correct answer)
Explanation: When analyzing simultaneous shifts in supply and demand, you need to track how each change affects both equilibrium price and quantity, then use the observed outcome to determine the relative magnitudes of the shifts. Here's what happened: The drought decreased supply (shifted supply curve left), while the fashion trend increased demand (shifted demand curve right). A decrease in supply alone would reduce quantity and increase price. An increase in demand alone would increase both quantity and price. Since the net result shows equilibrium quantity decreased, the supply reduction must have dominated. The correct answer is D because when equilibrium quantity falls despite an increase in demand, the decrease in supply must have been larger than the demand increase. Think of it as a tug-of-war: demand pulled quantity up while supply pulled it down, but since quantity ended up lower, supply's pull was stronger. Answer A is wrong because if demand increased more than supply decreased, equilibrium quantity would have risen, not fallen. Answer B is incorrect because equal-magnitude shifts would leave quantity unchanged while only affecting price. Answer C is wrong because we cannot definitively determine the price direction—while the supply decrease pushes price up and demand increase also pushes price up, the net effect on price depends on the specific magnitudes and shapes of the curves. Remember this key insight: when you observe the final equilibrium outcome, work backwards to determine which force dominated. The direction of quantity change tells you which shift was stronger, regardless of what happened to price.

Question 19

A city experiences a sudden, large increase in its population, causing a significant rightward shift in the demand for rental housing. The short-run supply of housing is known to be highly inelastic. What is the most likely immediate impact on the city's housing market?

  1. A significant shortage of housing will persist because prices are unable to adjust in the short run.
  2. A large increase in the quantity of available housing with only a small increase in housing prices.
  3. A large increase in housing prices with only a small increase in the quantity of available housing. (correct answer)
  4. A decrease in housing prices as the market anticipates new construction to meet demand.
Explanation: When analyzing housing market dynamics, you need to understand how supply and demand interact, especially when supply elasticity varies. This question tests your grasp of how markets respond to demand shocks when supply cannot easily adjust. A sudden population increase shifts housing demand rightward, meaning more housing is demanded at every price level. However, the key constraint here is that short-run housing supply is highly inelastic. This means the quantity of available housing cannot increase much even when prices rise significantly—you can't build apartments overnight. When demand increases but supply cannot respond proportionally, prices must do the heavy lifting to restore market equilibrium. The result is a large price increase with only a small increase in available housing quantity, making C correct. Option A incorrectly assumes prices cannot adjust in the short run. While supply is constrained, prices can and do adjust quickly in most markets. Option B reverses the relationship—this would only occur if supply were highly elastic (easy to increase quickly). Option D suggests prices would fall, which contradicts basic supply and demand theory when demand increases and supply is constrained. Remember this pattern: when supply is inelastic and demand increases, expect large price changes with small quantity changes. Conversely, when supply is elastic, expect large quantity changes with small price changes. Housing markets are classic examples of inelastic short-run supply due to construction time, zoning laws, and land availability constraints.

Question 20

A severe frost damages a large portion of the orange crop. Oranges are the primary input for orange juice. Around the same time, the price of breakfast cereal, a good often consumed with orange juice, decreases. What is the net effect on the market for orange juice?

  1. The equilibrium quantity will decrease, but the effect on equilibrium price is indeterminate.
  2. The equilibrium price will increase, and the equilibrium quantity will decrease.
  3. Both the equilibrium price and quantity will decrease.
  4. The equilibrium price will increase, but the effect on equilibrium quantity is indeterminate. (correct answer)
Explanation: When you encounter questions involving simultaneous shifts in supply and demand, you need to analyze each shift separately, then determine the combined effect on price and quantity. The frost damages orange crops, reducing the supply of oranges (the primary input for orange juice). This supply decrease shifts the orange juice supply curve leftward, increasing price and decreasing quantity. Meanwhile, breakfast cereal prices fall. Since cereal and orange juice are complements (consumed together), cheaper cereal increases demand for orange juice, shifting the demand curve rightward. This demand increase raises both price and quantity. Combining these effects: both shifts push price upward, so equilibrium price will definitively increase. However, the quantity effects oppose each other—supply decrease reduces quantity while demand increase raises quantity. The net effect on quantity depends on which shift is larger in magnitude, making it indeterminate without additional information. Answer choice A incorrectly states quantity will decrease and price is indeterminate. This reverses the actual outcome. Answer choice B assumes the supply decrease dominates the demand increase for quantity, but we can't determine this from the given information. Answer choice C suggests both price and quantity fall, which ignores that both shifts push price upward and that demand increases from cheaper complements. Answer choice D correctly identifies that price will increase (both shifts raise price) while quantity's direction is indeterminate (opposing effects of unknown relative magnitude). Study tip: For simultaneous supply and demand shifts, first determine if the shifts reinforce each other or oppose each other for price and quantity separately. When effects oppose, the result is indeterminate.